Bug fixes

.agents/skills/impeccable/scripts/live/generation-preflight.mjs

@@ -0,0 +1,149 @@
+import { execFile } from 'node:child_process';
+import path from 'node:path';
+import { promisify } from 'node:util';
+
+const execFileAsync = promisify(execFile);
+const PREFLIGHT_TIMEOUT_MS = 15_000;
+
+// Per-target cache of the resolved source file. The wrap search walks the whole
+// project tree and was measured at ~7.6s on a large repo; it re-ran on every
+// generate for the same picked element (re-rolls, param passes). Keyed by the
+// target signature (locator + route), so it invalidates automatically when the
+// element or route changes; a failed resolution evicts its entry (see below).
+const sourceResolutionCache = new Map();
+
+/** Test/lifecycle hook: drop all cached source resolutions. */
+export function clearSourceResolutionCache() {
+  sourceResolutionCache.clear();
+}
+
+function targetSignature(event) {
+  const isInsert = event.mode === 'insert';
+  const target = isInsert ? insertTarget(event) : replaceTarget(event);
+  return JSON.stringify({
+    mode: isInsert ? 'insert' : 'replace',
+    position: isInsert ? target.position : null,
+    elementId: target.elementId || null,
+    classes: target.classes || null,
+    tag: target.tag || null,
+    pageUrl: event.pageUrl || null,
+  });
+}
+
+export function buildGenerationPreflight(event, scriptsDir, { cache = null } = {}) {
+  if (!event || event.type !== 'generate' || !event.id) return null;
+
+  const isInsert = event.mode === 'insert';
+  const target = isInsert ? insertTarget(event) : replaceTarget(event);
+  if (!target.elementId && !target.classes) return null;
+
+  const script = path.join(scriptsDir, isInsert ? 'live-insert.mjs' : 'live-wrap.mjs');
+  const args = [script, '--id', event.id, '--count', String(event.count || 3)];
+  // Compute the scaffold but do not write it into source for source-preview
+  // targets. The agent writes wrapper + variants atomically; a premature
+  // server-side write reloads the framework and strands the browser at 0/N.
+  // No-op on the svelte-component path, which never writes the route source.
+  args.push('--defer-source-write');
+  if (isInsert) args.push('--position', target.position);
+  if (target.elementId) args.push('--element-id', target.elementId);
+  if (target.classes) args.push('--classes', target.classes);
+  if (target.tag) args.push('--tag', target.tag);
+  if (target.text) args.push('--text', target.text);
+  if (!isInsert && event.pageUrl) args.push('--page-url', event.pageUrl);
+  const signature = targetSignature(event);
+  // A cached resolution points the helper straight at the file, skipping the
+  // tree search. The helper still reads current content, so line ranges stay
+  // fresh; only discovery is cached.
+  const cachedFile = cache ? cache.get(signature) : null;
+  if (cachedFile) args.push('--file', cachedFile);
+  return { script, args, mode: isInsert ? 'insert' : 'replace', signature };
+}
+
+/**
+ * Scaffold the source for a generate event before handing it to an agent.
+ *
+ * Async on purpose. This spawns `live-wrap.mjs`, which walks the project's
+ * source tree and can take seconds (measured at ~7.6s on a large repo when the
+ * element is not found, with a 15s ceiling). The live server is single-threaded
+ * and calls this while leasing a poll, so a synchronous spawn froze the whole
+ * server for that entire window: Accept and Discard POSTs, SSE progress
+ * broadcasts, and every other poll stalled behind it.
+ */
+export async function runGenerationPreflight(event, {
+  cwd = process.cwd(),
+  scriptsDir,
+  execFileImpl = execFileAsync,
+  timeoutMs = PREFLIGHT_TIMEOUT_MS,
+  cache = sourceResolutionCache,
+} = {}) {
+  const command = buildGenerationPreflight(event, scriptsDir, { cache });
+  if (!command) {
+    return { ok: false, skipped: true, reason: 'insufficient_locator' };
+  }
+
+  const startedAt = performance.now();
+  try {
+    const { stdout } = await execFileImpl(process.execPath, command.args, {
+      cwd,
+      encoding: 'utf-8',
+      timeout: timeoutMs,
+    });
+    const line = String(stdout).trim().split('\n').filter(Boolean).pop();
+    if (!line) throw new Error('preflight returned no scaffold metadata');
+    const scaffold = JSON.parse(line);
+    // Cache the resolved SOURCE file (route source, not the svelte manifest) so
+    // the next generate on this target skips the tree search.
+    const resolvedSource = scaffold.sourceFile || scaffold.file;
+    if (cache && command.signature && typeof resolvedSource === 'string') {
+      cache.set(command.signature, resolvedSource);
+    }
+    return {
+      ok: true,
+      mode: command.mode,
+      durationMs: performance.now() - startedAt,
+      scaffold,
+    };
+  } catch (error) {
+    // Evict a stale/failed resolution so the next attempt does a full search
+    // (the element may have moved out of the previously cached file).
+    if (cache && command.signature) cache.delete(command.signature);
+    return {
+      ok: false,
+      mode: command.mode,
+      durationMs: performance.now() - startedAt,
+      error: compactError(error),
+    };
+  }
+}
+
+function replaceTarget(event) {
+  return normalizeTarget(event.element || {});
+}
+
+function insertTarget(event) {
+  return {
+    ...normalizeTarget(event.insert?.anchor || {}),
+    position: event.insert?.position === 'before' ? 'before' : 'after',
+  };
+}
+
+function normalizeTarget(target) {
+  const classes = Array.isArray(target.classes)
+    ? target.classes.join(' ')
+    : String(target.classes || '').trim();
+  const text = typeof target.textContent === 'string'
+    ? target.textContent.trim().slice(0, 80)
+    : '';
+  return {
+    elementId: target.id || target.elementId || undefined,
+    classes: classes || undefined,
+    tag: target.tagName || target.tag || undefined,
+    text: text || undefined,
+  };
+}
+
+function compactError(error) {
+  const stderr = error?.stderr ? String(error.stderr).trim() : '';
+  const message = stderr.split('\n').filter(Boolean).pop() || error?.message || 'preflight failed';
+  return String(message).slice(0, 500);
+}